(-4x²-3y³)(12x²-9y³)= -3(4x²+3y³)(4x²-3y³)= -3(16x⁴-9y^6)= 27y^6 - 48x⁴5x-6(3x＋2)×(-2＋3x)＋54(x-1/3)×(x＋1/3)= 5x -6(9x² -4) +54(x²-1/...